Head protectors such as helmets may incorporate a fixed or movable transparent visor for protecting a person's eyes from the environment. Another form of protective equipment are face masks which fit over the nose and mouth of a user and seal to the user's face to protect the user from breathing noxious gases, and which are provided with a filter to filter environmental air or a supply of clean air from another source. An example of such a face mask is disclosed in U.S. Pat. No. 4,374,301. The face mask encloses the wearer's nose and mouth and provides a seal with the wearer's face. The mask includes an oxygen inlet coupled by a hose to a connector which releasably attaches to a receptacle on a helmet assembly. The opposite side of the mask can be secured to the helmet assembly by means of a strap.
Another example of a face mask for use with a helmet is described in U.S. Pat. No. 4,713,844. The face mask includes a frame which is shaped to register with the peripheral edge of an open face helmet and includes a peripheral face seal for sealing about a wearer's face. The face mask includes an upper ocular cavity having a pair of lenses and a lower oral-nasal cavity, both within the peripheral seal and which are divided by a partition. Each side of the mask has a bayonet fastener for fastening the mask to the helmet.
Another example of a helmet and face mask is disclosed in U.S. Pat. No. 5,078,130. The face mask is rotatably mounted to the helmet so that it can be moved between lowered and raised positions, and the mounting also enables the face mask to be slidably moved towards and away from a wearer's face in the lowered position. The face mask includes an internal seal which forms an oral-nasal cavity between the nose and chin of a wearer. A coupling mechanism is provided for coupling the face mask to a clean air supply. When in the lowered position, the face mask can be selectively moved between a position away from a wearer's face where the seal is broken so that the wearer can breathe ambient air, and a position in which the seal seals the face mask to a wearer's face to isolate the oral-nasal cavity from ambient air. The face mask includes an integrated window above the oral-nasal cavity.
Other forms of known protective equipment include transparent protective eyewear which generally have some retention system, for example a strap for retaining the eyewear on the head of a user.